Appendix C SCSI and FC-AL Devices

SCSI Target ID Number Addressing

Media Tray

The default SCSI ID numbers for devices in the media tray are:

Table C-1 Media Tray Default SCSI ID Numbers

Device	ID
CD-ROM drive	6
Tape drive	5

Internal Disk Drives

The default ID numbers for internal disk drives are:

Table C-2 Internal Disk Drive Default ID Numbers

Drive Bay	ID Number
0 (boot disk)	0
1	1
2	2
3	3
4	4
5	5
6	6
7	7

Device Naming Conventions

SCSI and FC-AL devices are identified by path names or aliases.

A full path name can be of the form, /sbus@1f,0/cgsix@1,0.

A short path name does not include address information. For example, the full path name shown above can be shortened to /sbus/cgsix. This form of name can be ambiguous if more than one of the devices is installed.

An alias is another form of short name. Use the OpenBoot devalias command to list current aliases.

Some common aliases are:

Table C-3 Examples of Alias Names

Alias	Full Path Name
net	/sbus@3,0/SUNW,hme@3,8c00000
cdrom	/sbus@3,0/SUNW,fas@3,8800000/sd@6,0:f
ttya	/central/fhc/zs@0,902000:a
ttyb	/central/fhc/zs@0,902000:b
screen	/SUNW,ffb@2,0
disk	/sbus@2,0/SUNW,socal@d,10000/sf@0,0/ssd@0,0

SCSI Cable Length

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Note -

Do not use the onboard SCSI connector of the I/O+ board in slot 1. The onboard SCSI connector for the board in slot 1 connects to the media tray at the front of the system (the media tray contains the CD-ROM drive and a slot for an optional second SCSI drive).

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You can connect SCSI devices to the onboard SCSI connector on an I/O+ board in any slot except slot 1.

You can use the SBus slots on any I/O+ board for SCSI interface cards.

The maximum combined length for a string of SCSI cables is 6 meters for non-differential cables. For differential SCSI cables, the maximum is 25 meters.

To calculate the total length of a SCSI string, include external cables, internal cables, and printed traces. Table C-4 lists measurements for Enterprise servers.

Table C-4 Internal SCSI Lengths (Approximate)

Location	Internal Length
SBus+ I/O board	0.43 meter
Graphics+ I/O board	0.43 meter

SCSI Termination

The I/O+ board in slot 1 of any Enterprise server must be terminated. This slot connects to the internal CD-ROM drive and optional tape drive.

The SCSI bus on an I/O+ board in any other slot must be terminated only if SCSI devices are connected to that board.

Fiber Cable Length

Use a 2-meter cable to ensure that the 1.0 inch minimum bend radius rule for fiber optic cables is observed.

The interface board, together with interconnecting fiber optic cabling, provides four independent FC-AL loops between the host I/O+ board and the internal fiber optic disks.